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Congiu L, Granato V, Jakovcevski I, Kleene R, Fernandes L, Freitag S, Kneussel M, Schachner M, Loers G. Mice Mutated in the Third Fibronectin Domain of L1 Show Enhanced Hippocampal Neuronal Cell Death, Astrogliosis and Alterations in Behavior. Biomolecules 2023; 13:776. [PMID: 37238646 PMCID: PMC10216033 DOI: 10.3390/biom13050776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/25/2023] [Accepted: 04/26/2023] [Indexed: 05/28/2023] Open
Abstract
Adhesion molecules play major roles in cell proliferation, migration, survival, neurite outgrowth and synapse formation during nervous system development and in adulthood. The neural cell adhesion molecule L1 contributes to these functions during development and in synapse formation and synaptic plasticity after trauma in adulthood. Mutations of L1 in humans result in L1 syndrome, which is associated with mild-to-severe brain malformations and mental disabilities. Furthermore, mutations in the extracellular domain were shown to cause a severe phenotype more often than mutations in the intracellular domain. To explore the outcome of a mutation in the extracellular domain, we generated mice with disruption of the dibasic sequences RK and KR that localize to position 858RKHSKR863 in the third fibronectin type III domain of murine L1. These mice exhibit alterations in exploratory behavior and enhanced marble burying activity. Mutant mice display higher numbers of caspase 3-positive neurons, a reduced number of principle neurons in the hippocampus, and an enhanced number of glial cells. Experiments suggest that disruption of the dibasic sequence in L1 results in subtle impairments in brain structure and functions leading to obsessive-like behavior in males and reduced anxiety in females.
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Affiliation(s)
- Ludovica Congiu
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany (R.K.); (S.F.); (M.K.)
| | - Viviana Granato
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany (R.K.); (S.F.); (M.K.)
| | - Igor Jakovcevski
- Institut für Anatomie und Klinische Morphologie, Universität Witten/Herdecke, 58455 Witten, Germany;
| | - Ralf Kleene
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany (R.K.); (S.F.); (M.K.)
| | - Luciana Fernandes
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany (R.K.); (S.F.); (M.K.)
| | - Sandra Freitag
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany (R.K.); (S.F.); (M.K.)
| | - Matthias Kneussel
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany (R.K.); (S.F.); (M.K.)
| | - Melitta Schachner
- Keck Center for Collaborative Neuroscience, Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08554, USA
| | - Gabriele Loers
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany (R.K.); (S.F.); (M.K.)
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Weger M, Sandi C. High anxiety trait: A vulnerable phenotype for stress-induced depression. Neurosci Biobehav Rev 2018; 87:27-37. [DOI: 10.1016/j.neubiorev.2018.01.012] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/14/2018] [Accepted: 01/21/2018] [Indexed: 11/25/2022]
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van der Kooij MA, Grosse J, Zanoletti O, Papilloud A, Sandi C. The effects of stress during early postnatal periods on behavior and hippocampal neuroplasticity markers in adult male mice. Neuroscience 2015; 311:508-18. [PMID: 26548415 DOI: 10.1016/j.neuroscience.2015.10.058] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 10/23/2015] [Accepted: 10/30/2015] [Indexed: 12/25/2022]
Abstract
Infancy is a critical period for brain development. Emerging evidence indicates that stress experienced during that period can have long-term programming effects on the brain and behavior. However, whether different time periods represent different vulnerabilities to the programming of different neurobehavioral domains is not yet known. Disrupted maternal care is known to interfere with neurodevelopmental processes and may lead to the manifestation of behavioral abnormalities in adulthood. Mouse dams confronted with insufficient bedding/nesting material have been shown to provide fragmented maternal care to their offspring. Here, we compared the impact of this model of early-life stress (ELS) during different developmental periods comprising either postnatal days (PNDs) 2-9 (ELS-early) or PND 10-17 (ELS-late) on behavior and hippocampal cell adhesion molecules in male mice in adulthood. ELS-early treatment caused a permanent reduction in bodyweight, whereas this reduction only occurred transiently during juvenility in ELS-late mice. Anxiety was only affected in ELS-late mice, while cognition and sociability were equally impaired in both ELS-treated groups. We analyzed hippocampal gene expression of the γ2 subunit of the GABAa receptor (Gabrg2) and of genes encoding cell adhesion molecules. Gabrg2 expression was increased in the ventral hippocampus in ELS-late-treated animals and was correlated with anxiety-like behavior in the open-field (OF) test. ELS-early-treated animals exhibited an increase in nectin-1 expression in the dorsal hippocampus, and this increase was associated with the social deficits seen in these animals. Our findings highlight the relevance of developmental age on stress-induced long-term behavioral alterations. They also suggest potential links between early stress-induced alterations in hippocampal Gabrg2 expression and the developmental programming of anxiety and between changes in hippocampal nectin-1 expression and stress-induced social impairments.
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Affiliation(s)
- M A van der Kooij
- Laboratory of Behavioral Genetics, Brain Mind Institute, School of Life Sciences, Ecole Polytèchnique Fédérale de Lausanne (EPFL), Switzerland; Johannes Gutenberg University Medical Centre, Department of Psychiatry and Psychotherapy and Focus Program Translational Neurosciences, Mainz, Germany
| | - J Grosse
- Laboratory of Behavioral Genetics, Brain Mind Institute, School of Life Sciences, Ecole Polytèchnique Fédérale de Lausanne (EPFL), Switzerland
| | - O Zanoletti
- Laboratory of Behavioral Genetics, Brain Mind Institute, School of Life Sciences, Ecole Polytèchnique Fédérale de Lausanne (EPFL), Switzerland
| | - A Papilloud
- Laboratory of Behavioral Genetics, Brain Mind Institute, School of Life Sciences, Ecole Polytèchnique Fédérale de Lausanne (EPFL), Switzerland
| | - C Sandi
- Laboratory of Behavioral Genetics, Brain Mind Institute, School of Life Sciences, Ecole Polytèchnique Fédérale de Lausanne (EPFL), Switzerland.
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Lin AL, Zheng W, Halloran JJ, Burbank RR, Hussong SA, Hart MJ, Javors M, Shih YYI, Muir E, Solano Fonseca R, Strong R, Richardson AG, Lechleiter JD, Fox PT, Galvan V. Chronic rapamycin restores brain vascular integrity and function through NO synthase activation and improves memory in symptomatic mice modeling Alzheimer's disease. J Cereb Blood Flow Metab 2013; 33:1412-21. [PMID: 23801246 PMCID: PMC3764385 DOI: 10.1038/jcbfm.2013.82] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 04/04/2013] [Accepted: 04/23/2013] [Indexed: 12/14/2022]
Abstract
Vascular pathology is a major feature of Alzheimer's disease (AD) and other dementias. We recently showed that chronic administration of the target-of-rapamycin (TOR) inhibitor rapamycin, which extends lifespan and delays aging, halts the progression of AD-like disease in transgenic human (h)APP mice modeling AD when administered before disease onset. Here we demonstrate that chronic reduction of TOR activity by rapamycin treatment started after disease onset restored cerebral blood flow (CBF) and brain vascular density, reduced cerebral amyloid angiopathy and microhemorrhages, decreased amyloid burden, and improved cognitive function in symptomatic hAPP (AD) mice. Like acetylcholine (ACh), a potent vasodilator, acute rapamycin treatment induced the phosphorylation of endothelial nitric oxide (NO) synthase (eNOS) and NO release in brain endothelium. Administration of the NOS inhibitor L-NG-Nitroarginine methyl ester reversed vasodilation as well as the protective effects of rapamycin on CBF and vasculature integrity, indicating that rapamycin preserves vascular density and CBF in AD mouse brains through NOS activation. Taken together, our data suggest that chronic reduction of TOR activity by rapamycin blocked the progression of AD-like cognitive and histopathological deficits by preserving brain vascular integrity and function. Drugs that inhibit the TOR pathway may have promise as a therapy for AD and possibly for vascular dementias.
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Affiliation(s)
- Ai-Ling Lin
- Research Imaging Institute, San Antonio, TX, USA
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5
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Kudryashova IV. Structural and functional modifications of presynaptic afferents: Do they correlate with learning mechanisms? NEUROCHEM J+ 2011. [DOI: 10.1134/s181971241104009x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Nakamura Y, Lee S, Haddox CL, Weaver EJ, Lemmon VP. Role of the cytoplasmic domain of the L1 cell adhesion molecule in brain development. J Comp Neurol 2010; 518:1113-32. [PMID: 20127821 DOI: 10.1002/cne.22267] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mutations in the human L1CAM gene cause X-linked hydrocephalus and MASA (Mental retardation, Aphasia, Shuffling gait, Adducted thumbs) syndrome. In vitro studies have shown that the L1 cytoplasmic domain (L1CD) is involved in L1 trafficking, neurite branching, signaling, and interactions with the cytoskeleton. L1cam knockout (L1(KO)) mice have hydrocephalus, a small cerebellum, hyperfasciculation of corticothalamic tracts, and abnormal peripheral nerves. To explore the function of the L1CD, we made three new mice lines in which different parts of the L1CD have been altered. In all mutant lines L1 protein is expressed and transported into the axon. Interestingly, these new L1CD mutant lines display normal brain morphology. However, the expression of L1 protein in the adult is dramatically reduced in the two L1CD mutant lines that lack the ankyrin-binding region and they show defects in motor function. Therefore, the L1CD is not responsible for the major defects observed in L1(KO) mice, yet it is required for continued L1 protein expression and motor function in the adult.
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Affiliation(s)
- Yukiko Nakamura
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
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7
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Gene expression profile in rat hippocampus with and without memory deficit. Neurobiol Learn Mem 2010; 94:42-56. [PMID: 20359541 DOI: 10.1016/j.nlm.2010.03.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 03/08/2010] [Accepted: 03/25/2010] [Indexed: 01/22/2023]
Abstract
The cholinergic neuronal system, through its projections to the hippocampus, plays an important role in learning and memory. The aim of the study was to identify genes and networks in rat hippocampus with and without memory deficit. Genome-scale screening was used to analyze gene expression changes in rats submitted or not to intraparenchymal injection of 192 IgG-saporin and trained in spatial/object novelty tasks. Results showed learning processes were associated with significant expression of genes that could be grouped into several clusters of similar expression profiles and that are involved in biological functions, namely lipid metabolism, signal transduction, protein metabolism and modification, and transcription regulation. Memory loss following hippocampal cholinergic deafferentation was associated with significant expression of genes that did not show similar cluster organization. Only one cluster of genes could be identified; it included genes that would be involved in tissue remodeling. More important, most of the genes significantly altered in lesioned rats were down-regulated.
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Tsoory M, Guterman A, Richter-Levin G. âJuvenile stressâ alters maturation-related changes in expression of the neural cell adhesion molecule L1 in the limbic system: Relevance for stress-related psychopathologies. J Neurosci Res 2010; 88:369-80. [DOI: 10.1002/jnr.22203] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Lavdas AA, Chen J, Papastefanaki F, Chen S, Schachner M, Matsas R, Thomaidou D. Schwann cells engineered to express the cell adhesion molecule L1 accelerate myelination and motor recovery after spinal cord injury. Exp Neurol 2010; 221:206-16. [DOI: 10.1016/j.expneurol.2009.10.024] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 10/30/2009] [Accepted: 10/31/2009] [Indexed: 11/30/2022]
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10
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Conboy L, Bisaz R, Markram K, Sandi C. Role of NCAM in Emotion and Learning. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 663:271-96. [DOI: 10.1007/978-1-4419-1170-4_18] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Kulahin N, Li S, Kiselyov V, Bock E, Berezin V. Identification of neural cell adhesion molecule L1-derived neuritogenic ligands of the fibroblast growth factor receptor. J Neurosci Res 2009; 87:1806-12. [DOI: 10.1002/jnr.22014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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12
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Bisaz R, Conboy L, Sandi C. Learning under stress: A role for the neural cell adhesion molecule NCAM. Neurobiol Learn Mem 2009; 91:333-42. [DOI: 10.1016/j.nlm.2008.11.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 10/19/2008] [Accepted: 11/07/2008] [Indexed: 12/19/2022]
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Ilin Y, Richter-Levin G. Enriched environment experience overcomes learning deficits and depressive-like behavior induced by juvenile stress. PLoS One 2009; 4:e4329. [PMID: 19180243 PMCID: PMC2631645 DOI: 10.1371/journal.pone.0004329] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Accepted: 10/09/2008] [Indexed: 12/14/2022] Open
Abstract
Mood disorders affect the lives and functioning of millions each year. Epidemiological studies indicate that childhood trauma is predominantly associated with higher rates of both mood and anxiety disorders. Exposure of rats to stress during juvenility (JS) (27–29 days of age) has comparable effects and was suggested as a model of induced predisposition for these disorders. The importance of the environment in the regulation of brain, behavior and physiology has long been recognized in biological, social and medical sciences. Here, we studied the effects of JS on emotional and cognitive aspects of depressive-like behavior in adulthood, on Hypothalamic-Pituitary-Adrenal (HPA) axis reactivity and on the expression of cell adhesion molecule L1 (L1-CAM). Furthermore, we combined it with the examination of potential reversibility by enriched environment (EE) of JS – induced disturbances of emotional and cognitive aspects of behavior in adulthood. Three groups were tested: Juvenile Stress –subjected to Juvenile stress; Enriched Environment – subjected to Juvenile stress and then, from day 30 on to EE; and Naïves. In adulthood, coping and stress responses were examined using the elevated plus-maze, open field, novel setting exploration and two way shuttle avoidance learning. We found that, JS rats showed anxiety- and depressive-like behaviors in adulthood, altered HPA axis activity and altered L1-CAM expression. Increased expression of L1-CAM was evident among JS rats in the basolateral amygdala (BLA) and Thalamus (TL). Furthermore, we found that EE could reverse most of the effects of Juvenile stress, both at the behavioral, endocrine and at the biochemical levels. The interaction between JS and EE resulted in an increased expression of L1-CAM in dorsal cornu ammonis (CA) area 1 (dCA1).
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Affiliation(s)
- Yana Ilin
- Department of Psychology, The Institute for the Study of Affective Neuroscience (ISAN), University of Haifa, Mount Carmel, Haifa, Israel
| | - Gal Richter-Levin
- Department of Psychology, The Institute for the Study of Affective Neuroscience (ISAN), University of Haifa, Mount Carmel, Haifa, Israel
- * E-mail:
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Hoschouer EL, Yin FQ, Jakeman LB. L1 cell adhesion molecule is essential for the maintenance of hyperalgesia after spinal cord injury. Exp Neurol 2008; 216:22-34. [PMID: 19059398 DOI: 10.1016/j.expneurol.2008.10.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 10/21/2008] [Accepted: 10/31/2008] [Indexed: 10/21/2022]
Abstract
Spinal cord injury (SCI) results in a loss of normal motor and sensory function, leading to severe disability and reduced quality of life. A large proportion of individuals with SCI also suffer from neuropathic pain symptoms. The causes of abnormal pain sensations are not well understood, but can include aberrant sprouting and reorganization of injured or spared sensory afferent fibers. L1 is a cell adhesion molecule that contributes to axonal outgrowth, guidance and fasciculation in development as well as synapse formation and plasticity throughout life. In the present study, we used L1 knockout (KO) mice to determine whether this adhesion molecule contributes to sensory dysfunction after SCI. Both wild-type (WT) and KO mice developed heat hyperalgesia following contusion injury, but the KO mice recovered normal response latencies beginning at 4 weeks post-injury. Histological analyses confirmed increased sprouting of sensory fibers containing calcitonin-gene related peptide (CGRP) in the deep dorsal horn of the lumbar spinal cord and increased numbers of interneurons expressing protein kinase C gamma (PKCgamma) in WT mice 6 weeks after injury. In contrast, L1 KO mice had less CGRP(+) fiber sprouting, but even greater numbers of PKCgamma(+) interneurons at the 6 week time point. These data demonstrate that L1 plays a role in maintenance of thermal hyperalgesia after SCI in mice, and implicate CGRP(+) fiber sprouting and the upregulation of PKCgamma expression as potential contributors to this response.
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Affiliation(s)
- Emily L Hoschouer
- Department of Physiology and Cell Biology, The Ohio State University Medical Center, Columbus, OH, USA
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Savvaki M, Panagiotaropoulos T, Stamatakis A, Sargiannidou I, Karatzioula P, Watanabe K, Stylianopoulou F, Karagogeos D, Kleopa KA. Impairment of learning and memory in TAG-1 deficient mice associated with shorter CNS internodes and disrupted juxtaparanodes. Mol Cell Neurosci 2008; 39:478-90. [PMID: 18760366 DOI: 10.1016/j.mcn.2008.07.025] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2008] [Revised: 07/29/2008] [Accepted: 07/31/2008] [Indexed: 10/21/2022] Open
Abstract
The cell adhesion molecule TAG-1 is expressed by neurons and glial cells and plays a role in axon outgrowth, migration and fasciculation during development. TAG-1 is also required for the clustering of Kv1.1/1.2 potassium channels and Caspr2 at the juxtaparanodes of myelinated fibers. Behavioral examination of TAG-1 deficient mice (Tag-1(-/-)) showed cognitive impairments in the Morris water maze and novel object recognition tests, reduced spontaneous motor activity, abnormal gait coordination and increased response latency to noxious stimulation. Investigation at the molecular level revealed impaired juxtaparanodal clustering of Caspr2 and Kv1.1/1.2 in the hippocampus, entorhinal cortex, cerebellum and olfactory bulb, with diffusion into the internode. Caspr2 and Kv1.1 levels were reduced in the cerebellum and olfactory bulb. Moreover, Tag-1(-/-) mice had shorter internodes in the cerebral and cerebellar white matter. The detected molecular alterations may account for the behavioural deficits and hyperexcitability in these animals.
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Affiliation(s)
- Maria Savvaki
- Department of Basic Science, University of Crete Medical School, and Institute of Molecular Biology and Biotechnology, Heraklion, Greece
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Galvan V, Zhang J, Gorostiza OF, Banwait S, Huang W, Ataie M, Tang H, Bredesen DE. Long-term prevention of Alzheimer's disease-like behavioral deficits in PDAPP mice carrying a mutation in Asp664. Behav Brain Res 2008; 191:246-55. [PMID: 18485495 DOI: 10.1016/j.bbr.2008.03.035] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2007] [Revised: 03/25/2008] [Accepted: 03/28/2008] [Indexed: 11/20/2022]
Abstract
The deficits of Alzheimer's disease (AD) are believed to result, at least in part, from neurotoxicity of beta-amyloid (Abeta), a set of 38-43 amino acid fragments derived from the beta-amyloid precursor protein (APP). In addition, APP generates the APP-C31 and Jcasp toxic fragments intracellularly by cleavage at Asp664. We reported that mutation of Asp664 to Ala in a FAD-human APP transgene prevented AD-like deficits but did not affect Abeta production or deposition in PDAPP mice, arguing that D664A plays a crucial role in the generation of AD-like deficits. Whether D664A simply delays or completely prevents AD-like deficits, however, remained undefined. To address this question, we performed behavioral studies longitudinally on a pretrained mouse cohort at 9 and 13 months (mo) of age. While behavioral deficits were present in PDAPP mice, performance of Tg PDAPP(D664A) mice was not significantly different from non-Tg littermates' across all ages tested. Moreover, aberrant patterns in non-cognitive components of behavior in PDAPP mice were ameliorated in PDAPP(D664A) animals as well. A trend towards poorer retention at 9 mo and poorer learning at 13 mo that did not reach statistical significance was observed in PDAPP(D664A) mice. These results support and extend recent studies showing that cleavage of APP at Asp664 (or protein-protein interactions dependent on Asp664) is a crucial event in the generation of AD-like deficits in PDAPP mice. Our results thus further demonstrate that the D664A mutation either completely precludes, or markedly delays (beyond 13 mo) the appearance of AD-like deficits in this mouse model of AD.
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Affiliation(s)
- Veronica Galvan
- Buck Institute for Age Research, 8001 Redwood Blvd., Novato, CA 94945, USA.
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17
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Zhang R, Sun XZ, Cui C, Sakata-Haga H, Sawada K, Ye C, Fukui Y. Spatial learning and expression of neural cell adhesion molecule L1 in rats X-irradiated prenatally. THE JOURNAL OF MEDICAL INVESTIGATION 2007; 54:322-30. [PMID: 17878682 DOI: 10.2152/jmi.54.322] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The present study was designed to present evidence to clarify the relationships between learning ability, neuronal cell adhesion molecule L1 expression and hippocampal structural changes in the rat model received X-irradiation at an embryonic stage (E15). Water maze task indicated that all of the irradiated rats failed to learn the task in the whole training procedure. Their latency to the platform and swimming distance were significant differences from those sham-treated controls. Histological studies showed that the hippocampal ectopias induced by X-rays in the CA1 were involved in the spatial learning impairment, in which they hampered normal processes in learning development and transmission of information. Number, size and positions of the ectopias in the dorsal parts of the hippocampus were confirmed to be related to degrees of spatial learning impairment. On the other hand, L1 expression in the hippocampus was examined with Western blot analysis. The results indicated a lower content of L1 in the irradiated rats. A decrease in L1 might be one of reasons to cause disorganization of the septohippocampal pathways. These findings suggest some mechanisms of spatial learning impairment can be attributed to the formation of the hippocampal ectopias and redaction of L1 following prenatal exposure to X-irradiation.
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Affiliation(s)
- Rui Zhang
- Department of Anatomy and Developmental Neurobiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
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Chen J, Wu J, Apostolova I, Skup M, Irintchev A, Kügler S, Schachner M. Adeno-associated virus-mediated L1 expression promotes functional recovery after spinal cord injury. Brain 2007; 130:954-69. [PMID: 17438016 DOI: 10.1093/brain/awm049] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Paucity of permissive molecules and abundance of inhibitory molecules in the injured spinal cord of adult mammals prevent axons from successful regeneration and, thus, contribute to the failure of functional recovery. Using an adeno-associated viral (AAV) vector, we expressed the regeneration-promoting cell adhesion molecule L1 in both neurons and glia in the lesioned spinal cord of adult mice. Exogenous L1, detectable already 1 week after thoracic spinal cord compression and immediate vector injection, was expressed at high levels up to 5 weeks, the longest time-period studied. Dissemination of L1-transduced cells throughout the spinal cord was wide, spanning over more than 10 mm rostral and 10 mm caudal to the lesion scar. L1 was not detectable in the fibronectin-positive lesion core. L1 overexpression led to improved stepping abilities and muscle coordination during ground locomotion over a 5-week observation period. Superior functional improvement was associated with enhanced reinnervation of the lumbar spinal cord by 5-HT axons. Corticospinal tract axons did not regrow beyond the lesion scar but extended distally into closer proximity to the injury site in AAV-L1-treated compared with control mice. The expression of the neurite outgrowth-inhibitory chondroitin sulphate proteoglycan NG2 was decreased in AAV-L1-treated spinal cords, along with reduction of the reactive astroglial marker GFAP. In vitro experiments confirmed that L1 inhibits astrocyte proliferation, migration, process extension and GFAP expression. Analyses of intracellular signalling indicated that exogenous L1 activates diverse cascades in neurons and glia. Thus, AAV-mediated L1 overexpression appears to be a potent means to favourably modify the local environment in the injured spinal cord and promote regeneration. Our study demonstrates a clinically feasible approach of promising potential.
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Affiliation(s)
- Jian Chen
- W. M. Keck Center for Collaborative Neuroscience, Department of Cell Biology and Neuroscience, Rutgers the State University of New Jersey, Piscataway, NJ 08854, USA
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Henninger N, Feldmann RE, Fütterer CD, Schrempp C, Maurer MH, Waschke KF, Kuschinsky W, Schwab S. Spatial learning induces predominant downregulation of cytosolic proteins in the rat hippocampus. GENES BRAIN AND BEHAVIOR 2007; 6:128-40. [PMID: 16643511 DOI: 10.1111/j.1601-183x.2006.00239.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Spatial learning is known to depend on protein synthesis in the hippocampus. Whereas the role of the hippocampus in spatial memory is established, the biochemical and molecular mechanisms underlying this process are poorly understood. To comprehend the complex pattern of protein expression induced by spatial learning, we analyzed alterations in the rat hippocampus proteome after 7 days of spatial learning in the Morris water maze. Forty Wistar rats were randomized into two groups. Animals of group A learned to localize a hidden platform in the water maze. Animals of group B served as controls and spent exactly the same time in the water maze as animals of group A. However, no platform was used in this test and the rats could not learn to localize the target. After the last trial, hydrophilic proteins from the hippocampus were isolated. A proteome-wide study was performed, based on two-dimensional gel electrophoresis and mass spectrometry. Compared with non-learning animals, 53 (70%) proteins were downregulated and 23 (30%) proteins were upregulated after 7 days in rats with spatial learning. The overall changes in protein expression, as quantified by the induction factor, ranged from -1.62 (downregulation to 62%) to 2.10 (upregulation by 110%) compared with controls (100%). Most identified proteins exhibit known functions in vesicle transport, cytoskeletal architecture, and metabolism as well as neurogenesis. These findings indicate that learning in the Morris water maze has a morphological correlate on the proteome level in the hippocampus.
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Affiliation(s)
- N Henninger
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA.
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20
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Da Silva WC, Bonini JS, Bevilaqua LRM, Medina JH, Izquierdo I, Cammarota M. Inhibition of mRNA synthesis in the hippocampus impairs consolidation and reconsolidation of spatial memory. Hippocampus 2007; 18:29-39. [PMID: 17853412 DOI: 10.1002/hipo.20362] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Using two different mRNA synthesis inhibitors, we show that blockade of hippocampal gene expression during restricted posttraining or postretrieval time windows hinders retention of long-term spatial memory for the Morris water maze task, without affecting short-term memory, nonspatial learning, or the functionality of the hippocampus. Our results indicate that spatial memory consolidation induces the activation of the hippocampal transcriptional machinery and suggest the existence of a gene expression-dependent reconsolidation process that operates in the dorsal hippocampus at the moment of retrieval to stabilize the reactivated mnemonic trace.
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Affiliation(s)
- Weber C Da Silva
- Centro de Memória, Instituto de Pesquisas Biomédicas, Pontifícia Universidade Católica do Rio Grande do Sul, Av. Ipiranga 6690, Porto Alegre, Rio Grande do Sul, Brasil
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21
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Bernreuther C, Dihné M, Johann V, Schiefer J, Cui Y, Hargus G, Schmid JS, Xu J, Kosinski CM, Schachner M. Neural cell adhesion molecule L1-transfected embryonic stem cells promote functional recovery after excitotoxic lesion of the mouse striatum. J Neurosci 2006; 26:11532-9. [PMID: 17093074 PMCID: PMC6674779 DOI: 10.1523/jneurosci.2688-06.2006] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We have generated a murine embryonic stem cell line constitutively expressing L1 at all stages of neural differentiation to investigate the effects of L1 overexpression on stem cell proliferation, migration, differentiation, cell death, and ability to influence drug-induced rotation behavior in an animal model of Huntington's disease. L1-transfected cells showed decreased cell proliferation in vitro, enhanced neuronal differentiation in vitro and in vivo, and decreased astrocytic differentiation in vivo without influencing cell death compared with nontransfected cells. L1 overexpression also resulted in an increased yield of GABAergic neurons and enhanced migration of embryonic stem cell-derived neural precursor cells into the lesioned striatum. Mice grafted with L1-transfected cells showed recovery in rotation behavior 1 and 4 weeks, but not 8 weeks, after transplantation compared with mice that had received nontransfected cells, thus demonstrating for the first time that a recognition molecule is capable of improving functional recovery during the initial phase in a syngeneic transplantation paradigm.
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Affiliation(s)
- Christian Bernreuther
- Zentrum für Molekulare Neurobiologie Hamburg, University of Hamburg, D-20251 Hamburg, Germany
- Institute for Neuropathology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
| | - Marcel Dihné
- Zentrum für Molekulare Neurobiologie Hamburg, University of Hamburg, D-20251 Hamburg, Germany
| | - Verena Johann
- Neurology Center, University Medical Center Rheinisch-Westfälische Technische Hochschule-Aachen, D-52074 Aachen, Germany, and
| | - Johannes Schiefer
- Neurology Center, University Medical Center Rheinisch-Westfälische Technische Hochschule-Aachen, D-52074 Aachen, Germany, and
| | - Yifang Cui
- Zentrum für Molekulare Neurobiologie Hamburg, University of Hamburg, D-20251 Hamburg, Germany
| | - Gunnar Hargus
- Zentrum für Molekulare Neurobiologie Hamburg, University of Hamburg, D-20251 Hamburg, Germany
| | - Janinne Sylvie Schmid
- Zentrum für Molekulare Neurobiologie Hamburg, University of Hamburg, D-20251 Hamburg, Germany
| | - Jinchong Xu
- Zentrum für Molekulare Neurobiologie Hamburg, University of Hamburg, D-20251 Hamburg, Germany
- Sino-German Center for Neuroscience, Dalian University Medical School, Dalian, Liaoning 116027, China
| | - Christoph M. Kosinski
- Neurology Center, University Medical Center Rheinisch-Westfälische Technische Hochschule-Aachen, D-52074 Aachen, Germany, and
| | - Melitta Schachner
- Zentrum für Molekulare Neurobiologie Hamburg, University of Hamburg, D-20251 Hamburg, Germany
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22
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Guterman A, Richter-Levin G. Neuromodulators of LTP and NCAMs in the amygdala and hippocampus in response to stress. EXS 2006; 98:137-48. [PMID: 17019886 DOI: 10.1007/978-3-7643-7772-4_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Possibly, at the onset of an emotional event the stress hormones permissively mediate plasticity. Specifically, CORT and NE stress hormones participate in modulation of memory consolidation processes in both the amygdala and the hippocampus. In addition, glucocorticoids and norepinephrin bound to adrenoceptors are also involved in modulating the regulation of NCAM polysialylation both in the amygdala and in the hippocampus. PSA-related synaptic remodeling is mobilized for memory formation in particularly challenging circumstances.
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Affiliation(s)
- Adi Guterman
- Department of Psychology, Faculty of Social Sciences, Brain and Behavior Research Center, University of Haifa, Israel
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23
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Brunskill EW, Ehrman LA, Williams MT, Klanke J, Hammer D, Schaefer TL, Sah R, Dorn GW, Potter SS, Vorhees CV. Abnormal neurodevelopment, neurosignaling and behaviour in Npas3-deficient mice. Eur J Neurosci 2005; 22:1265-76. [PMID: 16190882 DOI: 10.1111/j.1460-9568.2005.04291.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Npas3 is a member of the bHLH-PAS superfamily of transcription factors that is expressed broadly in the developing neuroepithelium. To study the function of this gene, mice deficient in Npas3 were generated and characterized. Npas3-/- mice were growth-retarded and exhibited developmental brain abnormalities that included a reduction in size of the anterior hippocampus, hypoplasia of the corpus callosum and enlargement of the ventricles. A number of behavioural abnormalities were identified in Npas3-/- mice including locomotor hyperactivity, subtle gait defects, impairment of prepulse inhibition of acoustic startle, deficit in recognition memory and altered anxiety-related responses. Characterization of neurosignaling pathways using several pharmacological agents revealed dysfunctional glutamate, dopamine and serotonin neurotransmitter signaling. Consistent with these findings, we identified a significant alteration in cortical PSD-95 expression, a PDZ-containing protein that has been shown to be involved in postsynaptic signal transduction. Together, our observations indicate an important role for Npas3 in controlling normal brain development and neurosignaling pathways.
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Affiliation(s)
- Eric W Brunskill
- Division of Cardiology, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA.
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Chen J, Bernreuther C, Dihné M, Schachner M. Cell Adhesion Molecule L1–Transfected Embryonic Stem Cells with Enhanced Survival Support Regrowth of Corticospinal Tract Axons in Mice after Spinal Cord Injury. J Neurotrauma 2005; 22:896-906. [PMID: 16083356 DOI: 10.1089/neu.2005.22.896] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Previous studies have indicated that the cell adhesion molecule L1 enhances neuronal survival and neurite outgrowth. L1-mediated promotion of neurite outgrowth has been shown to occur also in an inhibitory environment not only in vitro, but also in vivo. To further investigate the effects of L1 in spinal cord injury, we transfected embryonic stem cells with a plasmid encoding the full-length mouse L1 molecule under the control of PGK promoter. An embryonic stem cell line derived from C57BL/6J transgenic mice that express green fluorescent protein under control of the beta-actin promoter was transfected with L1 and injected into the lesion site of 3-month-old C57BL/6J female mice 7 days after compression injury. Non-transfected embryonic stem cells were detectable at the lesion site 3 days after transplantation, but lost their cellular integrity 7 days after transplantation and were barely detectable 1 month after transplantation. In contrast, L1-transfected embryonic stem cells were detected 1 month after transplantation in numbers comparable to those of the injected cells and demonstrated extended processes. Further, in contrast to the few detectable nontransfected stem cells that remained at the injection site 1 month post-transplantation, the L1-transfected embryonic stem cells had migrated rostrally and caudally from the lesion. Anterogradely labeled corticospinal tract axons showed interdigitation with L1-transfected embryonic stem cells and, in contrast to non-transfected stem cells, extended into the lesion site 1 month after transplantation and, in some cases, extended beyond it. Our observations encourage the use of L1-transfected embryonic stem cells that express L1 not only at the cell surface, but also as a soluble and secreted form. Their use could condition the inhibitory environment for homophilic L1-enhanced axon regrowth not only in spinal cord regeneration, but also in other lesion paradigms.
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Affiliation(s)
- Jian Chen
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany
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25
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Sandi C, Woodson JC, Haynes VF, Park CR, Touyarot K, Lopez-Fernandez MA, Venero C, Diamond DM. Acute stress-induced impairment of spatial memory is associated with decreased expression of neural cell adhesion molecule in the hippocampus and prefrontal cortex. Biol Psychiatry 2005; 57:856-64. [PMID: 15820706 DOI: 10.1016/j.biopsych.2004.12.034] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2004] [Revised: 10/25/2004] [Accepted: 12/17/2004] [Indexed: 12/27/2022]
Abstract
BACKGROUND There is an extensive literature describing how stress disturbs cognitive processing and can exacerbate psychiatric disorders. There is, however, an insufficient understanding of the molecular mechanisms involved in stress effects on brain and behavior. METHODS Rats were given spatial memory training in a hippocampus-dependent water maze task. We investigated how a fear-provoking experience (predator exposure) would affect their spatial memory and neural cell adhesion molecule (NCAM) levels in the hippocampus, prefrontal cortex (PFC), amygdala, and cerebellum. RESULTS Whereas the control (nonstress) group exhibited excellent memory for the hidden platform location in the water maze, the cat-exposed (stress) group exhibited a profound impairment of memory and a marked suppression of levels of the NCAM-180 isoform in the hippocampus. Predator stress produced a more global reduction of NCAM levels in the PFC but had no effect on NCAM levels in the amygdala and cerebellum. CONCLUSIONS This work provides a novel perspective into dynamic and structure-specific changes in the molecular events involved in learning, memory, and stress. The selective suppression of NCAM-180 in the hippocampus and the more general suppression of NCAM in the PFC provide insight into the mechanisms underlying the great sensitivity of these two structures to be disturbed by stress.
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Affiliation(s)
- Carmen Sandi
- Laboratory of Behavioral Genetics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
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26
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Zhu X, Zeisel SH. Gene expression profiling in phosphatidylethanolamine N-methyltransferase knockout mice. ACTA ACUST UNITED AC 2005; 134:239-55. [PMID: 15836921 DOI: 10.1016/j.molbrainres.2004.10.040] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2004] [Revised: 10/08/2004] [Accepted: 10/24/2004] [Indexed: 01/06/2023]
Abstract
Choline is derived from the diet as well as from de novo methylation of phosphatidylethanolamine catalyzed by phosphatidylethanolamine N-methyltransferase (PEMT). Pemt knockout mice have no endogenous synthesis of choline molecules. We previously reported that these mice have excess S-adenosylmethionine and hypermethylated DNA in brain, as well as increased mitosis in neural progenitor cells of the hippocampus in embryonic day 17 (E17) brain. In the present study, E17 fetal brains and adult brains were harvested and total RNA was extracted. In fetal brain, using gene expression profiling and Significance Analysis of Microarrays, we identified 107 significant genes with increased expression and 379 significant genes with decreased expression. In adult brain, we identified 381 significant genes with increased expression and 1037 significant genes with decreased expression. We observed significant changes in expression of genes regulating cell cycle (such as TP53, Fgf4, and Ing1), differentiation and neurogenesis (such as S100A4 and D14Ws), and phospholipid metabolism (such as Pip5k1a, Pitpn, and Pla2g6) as well as in a number of methyltransferase genes (including Gnmt). Some genes with expression known to be regulated by promoter methylation were suppressed in Pemt knockout brain (such as S100a4 and TP53). These findings are consistent with the biochemical changes that we previous reported in fetal brains from Pemt knockout mice. This is the first report of gene profiling in Pemt(-/-) mouse brain.
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Affiliation(s)
- Xiaonan Zhu
- Department of Nutrition, CB #7461, School of Public Health, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
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27
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Abstract
Stress has profound effects on brain structure and function, but the underlying mechanisms are still poorly understood. Recent studies imply that neuronal cell adhesion molecules of the immunoglobulin superfamily--NCAM and L1--are important mediators of the effects of stress on the brain. Chronic stress regimes that lead to hippocampal atrophy and spatial-learning impairment in rodents simultaneously induce a pattern of changes in cell adhesion molecule expression that fits with a role for these molecules in stress-induced neuronal damage and neuroprotective mechanisms. These findings highlight cell adhesion molecules as potential therapeutic targets to treat stress-related cognitive disturbances.
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Affiliation(s)
- Carmen Sandi
- Laboratory of Behavioral Genetics, Brain Mind Institute, Swiss Federal Institute of Technology, EPFL, CH-1015 Lausanne, Switzerland.
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28
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Qin S, Zheng F, Chen GH, Fang H, Wang XM, Zhou JN. Variable alternative spliced exon (VASE)-containing and VASE-lacking neural cell adhesion molecule in the dorsal and ventral hippocampus of SAMP8 mice. J Neurosci Res 2005; 80:838-44. [PMID: 15884017 DOI: 10.1002/jnr.20527] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The neural cell adhesion molecule (NCAM) is involved in the development and synaptic plasticity of the brain. Differential splicing of the variable alternative spliced exon (VASE) in the fourth immunoglobulin domain can dramatically change the functional properties of NCAM. This paper discusses our analysis of the levels of different expression of VASE-containing NCAM (NCAM-VASE(+)) and VASE-lacking NCAM (NCAM-VASE(-)) mRNAs in the dorsal and ventral hippocampus of senescence-accelerated mice (SAM). We further investigated the individual level of NCAM-VASE(+) and NCAM-VASE(-) in relation to the capacity for spatial learning and memory as assessed by a Morris water maze task. The results showed that the levels of both NCAM-VASE(+) and NCAM-VASE(-) were increased significantly in dorsal but not ventral hippocampus in aged SAMP8 mice. The mean latencies to find the hidden platform of the learning task on the last day were positively correlated with the levels of NCAM-VASE(+) in the dorsal hippocampus of SAMP8, which reveals that the mice with high levels of NCAM-VASE(+) have poor learning performances. These results suggest that the up-regulation of NCAM-VASE(+) could be involved in the impairments of spatial learning and memory.
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Affiliation(s)
- Song Qin
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Neurobiology, School of Life Science, University of Science and Technology of China, Anhui
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29
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Knafo S, Barkai E, Libersat F, Sandi C, Venero C. Dynamics of olfactory learning-induced up-regulation of L1 in the piriform cortex and hippocampus. Eur J Neurosci 2005; 21:581-6. [PMID: 15673458 DOI: 10.1111/j.1460-9568.2005.03862.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
L1 is a cell adhesion molecule implicated in the formation of neural circuits and synaptic plasticity. We have examined the sequence and time-frame in which modifications in the synaptic expression of L1 occur in the piriform cortex and hippocampus in the course of rule learning of an olfactory discrimination task. Rats were trained to choose the correct odour in a pair to be rewarded with drinking water. Such training requires 6-8 days on average before rats reach maximal performance. We observed a learning-induced L1 up-regulation that occurred at an early training stage in the piriform cortex but only after rule-learning establishment in the hippocampus. We suggest that the dynamics of L1 up-regulation may reflect the functional role of these brain regions in olfactory rule learning.
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Affiliation(s)
- Shira Knafo
- Faculty of Health Sciences and Zlotowski Centre for Neuroscience, Ben-Gurion University, Beersheva, Israel
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30
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Sandi C, Cordero MI, Merino JJ, Kruyt ND, Regan CM, Murphy KJ. Neurobiological and endocrine correlates of individual differences in spatial learning ability. Learn Mem 2004; 11:244-52. [PMID: 15169853 PMCID: PMC419726 DOI: 10.1101/lm.73904] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The polysialylated neural cell adhesion molecule (PSA-NCAM) has been implicated in activity-dependent synaptic remodeling and memory formation. Here, we questioned whether training-induced modulation of PSA-NCAM expression might be related to individual differences in spatial learning abilities. At 12 h posttraining, immunohistochemical analyses revealed a learning-induced up-regulation of PSA-NCAM in the hippocampal dentate gyrus that was related to the spatial learning abilities displayed by rats during training. Specifically, a positive correlation was found between latency to find the platform and subsequent activated PSA levels, indicating that greater induction of polysialylation was observed in rats with the slower acquisition curve. At posttraining times when no learning-associated activation of PSA was observed, no such correlation was found. Further experiments revealed that performance in the massed water maze training is related to a pattern of spatial learning and memory abilities, and to learning-related glucocorticoid responsiveness. Taken together, our findings suggest that the learning-related neural circuits of fast learners are better suited to solving the water maze task than those of slow learners, the latter relying more on structural reorganization to form memory, rather than the relatively economic mechanism of altering synaptic efficacy that is likely used by the former.
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Affiliation(s)
- Carmen Sandi
- Department of Psychobiology, Universidad Nacional de Educacion a Distancia, Ciudad Universitaria s/n, 28040 Madrid, Spain.
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